This invention relates generally to a security system for the deterrence of theft of electrical appliances or other property with electrical circuitry and more particularly to a security system which deters by limiting the operability of electrical appliances to the perimeters of a specified zone.
Various security systems exist within the prior art for the prevention of theft of property. One such system is disclosed in U.S. Pat. No. 4,559,529 to Bernhardt in which radio signals are transmitted to protect monitored articles. An audible alarm is triggered if an improper code is received. U.S. Pat. No. 3,710,371 to Whalen et al discloses a system which employs a mercury switch to energize an alarm, and the systems disclosed in U.S. Pat. Nos. 4,284,983 to Lent and 3,836,901 to Matto et al sound alarms if there is unauthorized disconnection of the monitored appliance and the appliance is moved from its original position. In addition, security systems disclosed in U.S. Pat. Nos. 3,794,989 to Manley et al and 3,484,775 to Cline trigger alarms when a monitored appliance is disconnected, and U.S. Pat. Nos. 4,573,042 to Boyd et al and 4,136,338 to Antenore disclose systems which sound alarms when physical parameters have been exceeded by a monitored appliance.
While the prior art provides various security systems for designated articles, there exists a need for a theft prevention system for electrical items with an effective deterrent alternative.